In the field of communications, the need for high-speed transmission of data including video and audio has continued to increase. Moreover, the need for reliability of network elements within these networks that allow for this type of data transmission is becoming increasingly important.
Such network elements include various configurations of traffic cards, control cards, clock source cards, cross-connect cards, etc. In certain network elements, functionalities of these different cards can be combined. For example, a control card can also include the clock source and cross-connect functionalities. In other network element configurations, the cross-connect and control card functionalities are combined into the same card, while the clock source functionality is segregated into a separate card.
Further, these network elements can include redundancy for the traffic cards, control cards, clock source cards, cross-connect cards, etc., wherein a given type of card can include both a primary and a secondary card. Accordingly, when a primary card is not functioning correctly, the secondary card becomes the active card and serves as the new primary card for the given functionality.
Disadvantageously, conventional approaches that allow for the switch from the primary to the secondary can result in a loss of data as well as a disruption to framing and clocking of such data. For example, assume that the configuration of a network element is such that the control card includes the clock source as well as the cross-connect functionality for a number of traffic cards. If the network element switches from the primary to the secondary card for this control card because the primary is not operating correctly, then (depending on when the switch occurred) data, framing and/or clocking can be lost within the cards of the network element.